The present document relates generally to wireless communication and more specifically to resource allocation in space-division multiple access (SDMA) wireless communication systems.
Wireless communication systems have become a prevalent means by which a majority of people worldwide has come to communicate. Wireless communication devices have become smaller and more powerful in order to meet consumer needs and to improve portability and convenience. Consumers have found many uses for wireless communication devices such as cellular telephones, personal digital assistants (PDAs) and the like, demanding reliable service and expanded areas of coverage.
System capacity is a typical constraint that limits the ability of a system to provide reliable service to communication devices within a given coverage area. Wireless communication systems utilize various techniques that contribute to increasing system capacity.
Space Division Multiple Access (SDMA) is a technique that can be implemented in a multiple antenna communication system. SDMA utilizes the spatial dimension to support more terminals for data or information transmissions. The SDMA utilizes the spatial signatures of the terminals and schedules multiple data transmissions on each link that have (ideally) orthogonal spatial signatures to one another.
A wireless communication system can implement SDMA in various ways. One method is to utilize beamforming or otherwise directional antenna patterns. However, SDMA systems utilizing beamformed or otherwise directional antenna may suffer from weak coverage areas between beams or increased interference due to overlapping beams.